Grinding wheel truing device



2 SheetsSheet 1 H. H. ASBRIDGE GRINDING WHEEL TRUING DEVICE Filed March21, 1938 Sept. 20, 1938.

a? a 1 1 I i a l/1111i x l 1938- H. H. ASBRIDGE I 2,130,711

GRINEING WHEEL TRUING DEVICE Filed March 21, 1938 2 Sheets-Sheet 2 Fig.4

Patented Sept. 20, 1938 PATENT OFFICE GRINDING WHEEL TRUING DEVICE HarryHales Asbridge,

Moss Lane, Ashton-on- Merscy, England, assignor to The Churchill MachineTool Company Limited, Broadheath, nearAltrincham, England, a Britishcompany Application March 21,

1938, Serial No. 197,268

In Great Britain March 31, 1937 Claims.

This invention relates to grinding wheeltruing devices for grinding orabrading machines, the

grinding wheel having anoperative face of circular or other form such asis requisite, for

journal bearings and thrust races.

The object of the present invention is to provide an improvedarrangement of the truing device in the machine and improved means forbringing such device into operation and causing it to produce thedesiredcontour on the grinding wheel.

The invention consists in a grinding wheel truing device carried uponthe worktable of a grinding machine, the device, being put into andoutof service by a movement transversely to the direction of theworktable, and being moved in an arc of a circle to give the correctwheel contour by stopping the movement of one of two intergeared orinterconnected parts.

The invention comprises a slide upon'the worktable capable of movementtransversely to the direction oi movement ofithe worktable, anda secondslide upon the above said slide capable of movement in the direction ofmovement of the worktable, means moving the first slideto wards thegrinding wheel as the workpiece moves on its way to the grindingposition, meansfor arresting the motion of the second slide so that.

it engages the workpiece, and means returning.

the first slide to its initial position to put the truing tool out ofservice.

Referring to the accompanying explanatory drawings:

Figure 1 is a plan view, Figure 2 across sectional view on the line 22of Figure 1, and Figure 3 a sectional view on the line 33 of Figure 2illustrating part of a grinding machine with 1 wheel truing means inaccordance with this invention.

Figure 4: is a side view, Figure 5 a plan and Figure 6 an end viewillustrating a modification wherein the truing tool is constrained tomove in a definite path by a former to produce the desired contour onthe grinding wheel.

The table (1 upon which the work headstock 13 carrying the revolvingwork holder 0 is mounted and which is moved towards the grinding wheelat to cause the latter to engage the workpiece e which may be a ballrace, carries a slide 1 which example, for grinding the races of .balltype is bolted to the table a by the bolts {1 where required; I

Upon the slide 1 is a second slide it which can be traversed back andforth upon the slide 1 by the hydraulic plunger 2'. The slide h hasthereon a topslide 7 which can be secured thereto in any position ofadjustment. .Such top slide comprises a bracket 7c, upon a vertical faceof which is traversible a slide m. The latter has a swivel bracket n.journalledtherein, such bracket carrying at its upper end the diamondtruing tool 0 and at its lower end the pinion p which engages the rack qupon the slide member f. A spring. 1"- in the bracket 70 tends to forcethe slide m to the right .in Figure 1 and an abutment s upon a bracketton the grinding wheel head arrests the motion of the slide m in adirection towards the grinding wheel head. If the slide or ceases tomove, but the slide Jccontinues to move towardsthe grinding wheel head,then the rack q will turn the pinion p and so the swivel bracket n. andtruing tool 0 about the axis of the swivel bracket which will cause thetool to true the grinding wheel to the correct peripheral contour.

The action of the mechanism is as follows:- The worktable t movestowards the grinding position, carrying with it. the slide 1 and theparts and .slides h and :i and m thereon. The cross traversing slide itis advanced by the hydraulic plunger 1 and brought against a micrometerstop it. When the diamond truing tool 0 is in position to commencetruing the grinding wheel at, the spring loaded slide m has its motionarrested by the fixed stop or abutment s, which results in the diamondtruing tool holder being turned through an arc of a circle about theaxis of the swivel bracketm by the rack q and pinion :0 so that truingof the grinding wheel with a correct circular contour is ensured. Whentruing is completed, the hydraulic pressure holding plunger 1' with thecross traversing slide h against the micrometer stop u is released,allowing such slide to return under the pressure of the spring 112. Theslide m at the same time moves clear of the stop or abutment s andreturns to its initial position, which causes the diamond tool holderalso to return to its initial position. The. wheel truing equipment isnow ready for the next wheel truing cycle. The worktable it continues tomove to the grinding position, when its motion is arrested for theactual grinding operation.

In the modification shown in Figures 4, 5 and 6, the truing tool 0 iscarried in a member n pivotally mounted upon apin 2 secured in theswivel bracket m The pivoted member n acts against the pressure of aspring 3 and carries in its rear a part 4 which rides upon a former 5secured upon the slide 11 In operation, when the slide m is arrested asdescribed in connection with the previous form of the invention, theswivel bracket 11 is turned by the rack q on the slide 7' and the pinion17 This results in the truing tool being turned through an arc of acircle about the axis of the swivel bracket n and at the same timereceiving a movement from the former towards or away from the axis ofthe grinding wheel (1 The above two movements combine to cause the tool0 to give the correct peripheral contour to the grinding wheel.

The present invention may be applied to the machine described in priorPatent No. 2,005,332, or to other types of internal or external grindingmachines.

What I claim is:

1. A grinding wheel truing device for a grinding or abrading machinecomprising a worktable movable towards and from the grinding wheel, aslide upon the worktable capable of movement transversely to thedirection of movement of the worktable, and a second slide upon theaforesaid slide capable ofmovement in the direction of movement of theworktable and spring impelled in the direction towards the grindingwheel, means automatically moving the first slide towards the axis ofthe grinding wheel as the workpiece moves on its way to the grindingposition, means for arresting the motion of the second slide as it iscarried with the worktable in the direction towards the grinding wheelso that the first slide then moves relatively to the second slide, meansutilizing said relative movement to cause the wheel truing tool to movethrough the correct path for truing the grinding wheel before it engagesthe workpiece, and means returning the first slide to its initialposition to put the movement upon the main slide transversely to l thedirection of movement of the worktable, an additional slide adjustableupon the further slide in the direction of movement of the latter, a

still further slide movable upon the additional slide in the directionof movement of the worktable, a swivel bracket carrying the wheel truingtool mounted upon a vertical axis upon the said still further slide, apinion secured to said swivel bracket coaxially therewith, a rack uponsaid additional slide engaged by said pinion, a spring to move the stillfurther slide in the direction towards the grinding wheel and a stop orabutment to arrest its movement when the worktable is carrying the mainslide towards the grinding wheel head, automatic means to move thefurther slide to cause the truing tool to engage the grinding wheel asthe worktable moves towards the grinding wheel and the still furtherslide to come into the path of the stop or abutment, and automatic meansto return the said further slide to its initial position after thetruing operation.

3. A grinding wheel truing device as claimed in claim 1 having a swivelbracket upon said second slide, means actuated by relative movementbetween said first and second slides to turn said swivel bracket, apivotal member upon said swivel bracket, a grinding wheel truing toolupon said pivotal member, a spring acting upon said pivotal member tomove said tool away from the grinding wheel, a cam track upon said firstslide and a cam track follower upon said pivotal member moving over saidcam track as said swivel member turns to move said truing tool towardsthe grinding wheel as required.

4. A grinding wheel truing device as claimed in claim 2 having a swivelbracket upon said still further slide, means actuated by relativemovement between said further and still further slides in turn saidswivel bracket, a pivotal member upon said swivel bracket, a grindingwheel truing tool upon said pivotal member, a spring acting upon saidpivotal member to move said tool away from the grinding wheel, a camtrack'upon said further slide and a cam track follower upon said pivotalmember moving over said cam track as said swivel member turns to movesaid truing tool towards the grinding wheel as required.

5. A grinding wheel truing device as claimed in claim 2 wherein saidtruing tool is mounted in a part of said swivel bracket off-set from theaxis of said swivel bracket and is adjustable towards and from saidaxis.

HARRY HALES ASBRIDGE.

